Figure 3
From: MZB1 enables efficient interferon α secretion in stimulated plasmacytoid dendritic cells
Mzb1−/− pDCs exhibit an improper ER stress response due to the impaired activation of the ATF6 pathway. (A) Box plot of qRT-PCR analysis to determine the relative Hspa5 (BiP) and Ddit3 (CHOP) mRNA levels after stimulation of Mzb1+/+ and Mzb1−/− pDCs with CpG A for 24 h. mRNA levels were normalized to those of 18S rRNA. Numbers of independent samples (n) are indicated below the graph. (B) qRT-PCR analysis of Hspa5 (BiP) and Ddit3 (CHOP) mRNA at basal levels in unstimulated pDCs. (C) Immunoblot analysis to detect uncleaved and cleaved ATF6 (approx. 55 kDa) in CpG A-stimulated pDCs. GAPDH serves as a loading control. IgH indicates residual IgH from the serum and * indicates an unknown cross-reacting protein. Uncropped blots are shown in Supplementary Fig. S3D. (D) ELISA-based quantification of the secreted IFNα in the supernatant of 105 Mzb1+/+ and Mzb1−/− pDCs that were untreated or treated with the ATF6 inhibitor AEBSF at 100 µM. (E) ELISA-based quantification of secreted IFNα in the supernatant of Mzb1+/+ and Mzb1−/− pDCs, untreated or treated with the ATF6 inhibitor Ceapin A7 at 3 µM. Each dot represents an individual pDC culture derived from an individual mouse. Statistical difference between the mean was analyzed by an unpaired two-tailed Student’s t-test. *P ≤ 0.05; **P ≤ 0.005. Error bars show SD. ns, non-significant.
